Pompeo and Trump appear to be in lockstep, which could boost his credibility when dealing with foreign countries and North Korea.

President Donald Trump made the surprise announcement on Tuesday that he would replace Secretary of State Rex Tillerson with CIA Director Mike Pompeo, putting an end to a visibly turbulent relationship between the president and his top diplomat.

Tillerson's dismissal just weeks before Trump is due to meet with North Korean leader Kim Jong Un has shocked observers, but according to an expert, it may be for the best.

Time and time again, Trump appeared to contradict Tillerson in tweets or speeches, something which harmed the diplomat's credibility with foreign governments, according to Abraham Denmark, director of the Asia Program at the Wilson Center.

"One of the key features for any negotiator is that they have to be able to credibly represent their leadership," Denmark, a former deputy assistant secretary of defense for East Asia, told South Korea's Yonhap News. "That your counterpart knows that whatever deal you make, you know that your boss will back you up."

"If Pompeo can credibly say he represents the president and if the president is able to convey that sort of representational status, then it may make Pompeo a more credible negotiator in that, potentially more than Tillerson was, just because of the differences he had with the president," said Denmark.

Where Tillerson and Trump often appeared at odds, Pompeo and Trump meet every day and appear in lockstep. Additionally, Tillerson reportedly held back Trump from striking North Korea, while Pompeo has come off more hawkish.

"You can say it's not a good sign in terms of diplomacy, just because Pompeo seems a little bit more hard on North Korea than Tillerson," Sue Mi Terry, senior fellow for Korea at the Center for Strategic and International Studies told Yonhap.